Re: [tcpinc] TCP-ENO draft 04 posted

Hi, all,

I'm very confused by the new SYN data text.

First, if you really want state based on previous connections that
allows early use of SYN data  before the 3WHS, that seems to be the very
definition of TFO. So declaring that this solution is valid only where
TFO isn't used seems the opposite of what I would expect.

Second, the text doesn't cover the case where the endpoint abilities
have changed. Unless you use TFO cookies to verify that ability, you
should not assume you know it. Which means you can easily be sending
data you need to unroll - and the only safe way to do that (if the
endpoint turns out to be non-ENO even if you assumed otherwise) is to
terminate the connection.

Third, the claim that "Using data in SYNs deviates..." is incorrect.
Data in the SYN is valid for TCP. Did you mean "acting on received data
in the SYN before the 3WHS in the absence of TFO deviates..."?

Joe

On 7/29/2016 2:17 PM, dm-list-tcpcrypt@scs.stanford.edu wrote:
> I just posted a new draft of TCP-ENO, available here:
>
>         https://datatracker.ietf.org/doc/draft-ietf-tcpinc-tcpeno/
>
> This reflects the issues discussed in Berlin, as well as the first cut
> at data in SYN segments.  Note that these changes are all open for
> discussion, I just think that the discussion will be more useful if
> framed in terms of concrete language of a draft document.  For that
> reason, we will aim for shorter iteration cycles on ENO, and once ENO
> stabilizes start updating the other documents to match.
>
> Notable changes:
>
>   * Specs are now TEPs.
>
>   * General suboption renamed global suboption, and refered to more
>     consistenly that way.
>
>   * 'cs' (configuration/spec) bits in an initial suboption byte are now
>     'glt' (global/length/TEP).
>
>   * The 'm' bit is gone, and we now have z1, z2, z3 in the global
>     suboption.
>
>   * Length word is gone.
>
>   * New Data in SYN segments section.
>
>   * IANA considerations:  added some if(TBD == 69) instructions for the
>     RFC-editor, and made clear legacy use of 69 can break connection and
>     MUST be disabled if it can't be upgraded.
>
> David
>
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